MBB 222 Study Guide - Final Guide: Pyrimidine Dimer, Dna Glycosylase, Ap Endonuclease

15 views2 pages

Document Summary

The remaining nick is sealed by dna ligase. Enzyme that recognizes dna lesions and removes the affected base by cleaving the n-glycosyl bond. Each dna glycosylase is specific for one type of lesion. Ex. ) for cytosine deamination (forming uracil), base-excision repair is done using uracil dna glycosylase. Ap site (abasic site): the apurinic/apyrimidinic site in dna created by cleavage from dna glycosylase. Ap endonuclease: enzymes that cut the dna strand containing the ap site. This repair is used for dna lesions that cause large distortions in the helical structure of dna. A multisubunit enzyme hydrolyzes the phosphodiester bonds on either side of the distortion. The excised nucleotides are released from the duplex with the help of a helicase. The gap is filled in by dna pol i and the nick is ligated with dna ligase. Mbb222 exam vocab definitions: base/nucleotide-excision and pyrimidine dimer. When the offending base is removed and replaced.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers

Related Documents

Related Questions